The iPhone 4S is not the last major project that Steve Jobs worked on, according to one analyst. That would be the next iPhone--let's call it the iPhone 5.

The next-generation iPhone "was the last project that Steve Jobs was intimately involved with from concept to final design. For that reason...this product will establish the high water mark for iPhone volumes," Ashok Kumar, an analyst at Rodman & Renshaw, wrote in a research note this week. He expects the iPhone 5 to be a "cult classic" because of Jobs' involvement.

In the note, Kumar said the phone will have a slimmer profile and larger screen size but with the same dimensions as the iPhone 4S (the relatively-small 3.5-inch screen is not one of the 4S' best features). The iPhone is also expected to have LTE, or Long Term Evolution--what's sometimes referred to as 4G.

Another source, who I spoke with this week and who claims to have knowledge of the redesign, said the iPhone 5 is a "complete redesign. This is a very large project that Steve dedicated all of his time to. He was not that involved in the 4S because his time was limited."

That makes sense to me. Cosmetically, the iPhone 4S is identical to the iPhone 4. So no big change here. And though the 4S has been revamped on the inside, in some respects, it carries over technology already in the iPad 2: the same dual-core processor, same memory capacity, same accelerometer, same gyroscope, among other similarities.

So, it's probably not unreasonable to expect the iPhone 5 to be a "complete redesign," as the source said--meaning both externally and internally, though probably less so internally when compared with pronounced user-facing changes like the display size. (No telling what kind of plans Apple has on the software front: iOS 6? Siri 2?)

The iPhone 5 should debut around the time of Apple's Developer's Conference in the summer of 2012, according to Kumar's research note.